Close encounter with Pluto

Posted on July 17, 2015 by janstu

In an earlier post, Close Encounters , I mentioned three memorable astronomical events in 2015. One of them was the flyby by the New Horizons spacecraft of the (dwarf) planet Pluto on 14 July at 11:49:58 UTC (7:49:58 pm Malaysian time)

One day earlier, when the New Horizons was still a respectable 800.000 km away from Pluto, it took this picture.The heart-shaped region, the smooth surface, caused already much excitement

New Horizons was approaching Pluto at a speed of ~ 50.000 km/h, so the flyby was near. At this high speed the observation window for taking close-up pictures was narrow. It was decided to stop communicating with the spacecraft during the flyby, as the on-board computers would be busy collecting data. There was a lot of tension in the control room during the blackout. Here is the response when the first signal of New Horizons after the flyby is received. Mind you, it takes about 4.5 hours for light and radio signals to cross over form the spacecraft to Earth, as the distance to Pluto is about 5 billion km at the moment.

This first signal was only a sanity signal that everything was working normally. Transmission of the images is a time-consuming process. It was only the next day that NASA published the first detailed image.

Many surprises. The surface looks very smooth, scientists think it can not be more than a few hundred million year old. Has Pluto still an active interior? And there are mountains, up to 3 km high. They might consist of water ice.

A second picture has been published today, details of Pluto’s (principal) moon, Charon.

More excitement. Impact craters here, but what is this strange feature in the top left corner? More pictures will arrive and hopefully be published in the coming days. But the analysis will take months if not years.

New Horizons has done a marvelous job. It will now pass through the Kuiper Belt and leave our solar system. You can follow the spacecraft on the New Horizons website

What about the two other events?

Dawn has successfully entered orbit around Ceres and is still observing the asteroid. The white dots on its surface have not yet been explained. Here is a collage of images taken by Dawn. The Dawn Blog is still online and active

Finally Rosetta and Philae

Rosetta is still orbiting comet 67P, which is now on its way to perihelion, the closest distance to the Sun. Perihelion will be reached on 13 August. Already the comet is feeling the heat of the Sun and partly evaporating. This picture was taken on 7 July

Mixed news about Philae. There was huge excitement when it came out of hibernation on 13 June and “talked” for a few minutes with Rosetta. But after that, communication has been intermittent, for reasons unknown. However, ten days ago, Philae has contacted Rosetta again and actually transferred data from one of its on-board experiments! The scientists are hopeful that it will get more active the next few weeks. Read more on the Rosetta/Philae blog

I will update this post when more news/pictures become available

Update 18-7-2015

Yesterday NASA published another picture, a detail of the heart-shaped area , which has been provisionally named Sputnik Plain. Some features have been identified. This icy plain can not be more than 100 million old. More details here

Anybody out there?

Posted on July 3, 2015 by janstu

When you have followed my blog posts, you will know that I am a supporter of the Rare Earth Hypothesis. Mind you, I will be more than happy if proof of extraterrestrial life is found, but for the time being, I think we may well be alone in the Universe..:-(

Actually, for many years already I am participating in the SETI@home project. SETI stands for Search for ExtraTerrestrial Intelligence. The purpose of the project is to analyse radio signals for signs of intelligent life in the universe, and it is doing this by what is called distributed computing. The data to be analysed come from the Arecibo radio telescope in Puerto Rico.

More than 120.000 PC’s all over the world take part, my PC is one of them. When my computer is idle, it starts analysing a data packet received from Arecibo. Results of the analysis are sent back to SETI, I receive a new data packet and so on…:-) Here is the Arecibo telescope (with its mirror diameter of 300 m the largest in the world) and a screenshot of my monitor while it is analysing the data. Visual output is a screen saver, moving around the screen all the time..

The project has started in 1999 but until now no sign of (intelligent) life has been found.

You might describe this activity as LISTENING : is there anybody in the universe trying to communicate with us?

What about SHOUTING : is anybody out there? That is the topic of this post. Making our (human) existence known to the universe.

The first attempt to send out a signal to the universe dates back to 1972. The Pioneer 10 space probe was going to explore Jupiter and would leave the solar system after the end of its mission. Carl Sagan , who had been active already in promoting SETI, suggested that a “plaque” should be attached to the space probe, with information about our human species. The left image gives an artist impression of the Pioneer 10, now traveling in outer space, far away from Earth. It might come close to Aldebaran, a red giant star, in about 2 million years..:-) The right image shows the Pioneer plaque, designed by Sagan and his wife.

For more info about the meaning of the various elements, click on the link above. Here I only want to mention that there was a discussion about the naked humans. Was that acceptable of “porn”? By the way, the male genitals are shown, but the female vagina is missing, so aliens will still be in doubt how we reproduce. Would they be able to interpret the info correctly? Here is a hilarious interpretation: the Real Pioneer Plaque

Five years later the two Voyager space probes 1 and 2 were launched, again to explore the outer solar system. They have been extremely successful and are still operational, after almost 40 years! The Voyager 1 is now 19.6 billion km away from Earth, you can check the actual distance here . It has on board a phonographic(!) record containing information about Earth and about us. A kind of time capsule! The left image shows an artist impression of the Voyager 1 with the location of the golden record clearly visible. The right image shows the cover of the Voyager Golden Record.

Mind you, in 1977 digital coding was not common, no jpeg or mp3 existed yet, it was all analog!. Here is a fascinating Table of Contents of the Golden Record. Please click on this link and be surprised. A welcome message by Jimmy Carter, at that time US president! Greetings in 55 languages. One of them in Dutch (yes!), another one in Indonesian, four Chinese dialects, but no Malay, nor Tamil..:-( Music, from classical until modern. But this time no picture of naked humans, thanks to a (still) prudish US..:-).

If ever an alien civilization would pick up this time capsule, would they be able to decipher it? Some sources doubt it, check this funny Gizmodo report

You might compare these first attempts with throwing a bottle in the ocean. Maybe somebody will ever find it. Can we get more active?

Yes, we can. In 1974 the Arecibo telescope, mentioned above, sent out the Arecibo message to the Universe. A sequence of 1679 zero’s and one’s. Why that number? Because it is a semi-prime, product of two large prime numbers 23 and 73. When you order the message, split in a matrix of 73 x 23, you will get this (in black and white!):

To “explain” this, the white part represents our decimal system, the green one the nucleotides in our DNA, the blue one the double helix. The red human has next to it the human size (in binary) and the human population (also in binary), but probably you understood that already, didn’t you…LOL? Yellow represents our solar system, the third planet is shifted to the left with the human standing on it. Easy, right?

But would you be able to reconstruct the content from this binary sequence?

000000101010100000000000010100000101000000010010001000100010010110010
101010101010101001001000000000000000000000000000000000000011000000000
000000000011010000000000000000000110100000000000000000010101000000000
000000000111110000000000000000000000000000000011000011100011000011000
100000000000001100100001101000110001100001101011111011111011111011111
000000000000000000000000001000000000000000001000000000000000000000000
000010000000000000000011111100000000000001111100000000000000000000000
110000110000111000110001000000010000000001000011010000110001110011010
111110111110111110111110000000000000000000000000010000001100000000010
000000000011000000000000000100000110000000000111111000001100000011111
000000000011000000000000010000000010000000010000010000001100000001000
000011000011000000100000000001100010000110000000000000001100110000000
000000110001000011000000000110000110000001000000010000001000000001000
001000000011000000001000100000000110000000010001000000000100000001000
001000000010000000100000001000000000000110000000001100000000110000000
001000111010110000000000010000000100000000000000100000111110000000000
001000010111010010110110000001001110010011111110111000011100000110111
000000000101000001110110010000001010000011111100100000010100000110000
001000001101100000000000000000000000000000000000111000001000000000000
001110101000101010101010011100000000010101010000000000000000101000000
000000001111100000000000000001111111110000000000001110000000111000000
000110000000000011000000011010000000001011000001100110000000110011000
010001010000010100010000100010010001001000100000000100010100010000000
000001000010000100000000000010000000001000000000000001001010000000000
01111001111101001111000

These communication attempts date back quite a long time. Here is a recent one. On 9 October 2008 a high-powered digital radio signal was sent towards the Gliese 581c extrasolar planet: called A message from Earth. Followers of my blog may remember Gliese 581 as the name of a star with more than one habitable planets in orbit. Here is the blog report: New extrasolar planet has been discovered

The distance is about 20 light year, the message will reach the star in early 2029. If “they” reply immediately , we may expect a reply around 2050…:-) Here is the Ukrainian (!) telescope used to send out the message, and a sketch of the Gliese 581 planetary system.

Let me end this post with a question:

Is it wise for us to make our presence known to the Universe?

Stephen Hawking is not so sure about it and he is not the only one. Contact with aliens could be risky. “If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans ,” he said. “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet.”

A contact with aliens might be very different from Spielberg’s Close Encounters of the Third Kind, my favourite science fiction movie, released in 1977.

About galaxy SDP.81

Posted on June 16, 2015 by janstu

This astronomy blog needs a fairly long introduction, sorry…:-)

Our Sun is one of the more than 100 billion stars in the Milky Way galaxy. Here is the Milky Way, as seen from Earth. Many of you may never have seen this “milky” band, because you need a clear sky without light pollution. Next to it an artist expression of the Milky Way with the location of our Sun indicated by a red arrow.

The Milky Way is one of the about 100 billion galaxies in the observable Universe. The Andromeda galaxy (left pic) is a close neighbour at a distance of about 2.5 million light-year. The picture to the right was taken by the Hubble telescope. This image shows about 10.000 galaxies!

Many of you will have seen (and admired) the images taken by the Hubble telescope. Here is the telescope, it is still orbiting Earth at an altitude of ~ 550 km. Next to it the probably most iconic Hubble image, nicknamed the Pillars of Creation.

But not many of you will have heard about the Herschel telescope! This space telescope has been operational from 2009 to 2013. Its major objective was to discover how the first galaxies formed and evolved, starting from clouds of gas and dust. These clouds are not yet hot enough to emit visible light, but they still emit (thermal) radiation with wavelengths in the far infrared. It is this far infrared and sub-millimeter radiation that Herschel has recorded. Here is the Herschel telescope and a picture, taken by it. Not as spectacular as the Hubble pictures, right?

Actually, each pinprick in this image is a galaxy! Or better, a galaxy “under construction”, still basically a contracting cloud of gas and dust, Hubble would not be able to see them. Most of these galaxies are billions of light years (ly) away, the radiation we receive now, has been sent out when the universe was young.

We are finally coming closer to SDP.81. It is one of the baby galaxies (ID81 in the image below), discovered by Herschel, at a distance of about 11.7 billion ly . Why is it (and a few more) so bright ?

Here comes the surprising answer: because its radiation has been magnified by a gravitational lens between this galaxy and earth!

A gravitational lens? Yes, Einstein’s General Theory of Relativity predicted that light can be bent by massive objects. Or, formulated more correctly, massive objects will curve the fabric of space-time. His theory was spectacularly confirmed in 1919 during a solar eclipse (and made Einstein instantaneously famous!) Here is a schematic diagram of this light bending.

In the case of SDP.81 a massive galaxy is located, 3.4 billion ly from Earth, exactly between us and SDP.81. A rare coincidence? Sure, but keep in mind that there are 100 billion galaxies..:-)

A gravitational lens works differently from a traditional lens where the light bending is strongest at the edge of the lens. Here it is the other way around, bending is stronger near the center. When the alignment is perfect the (magnified) image becomes a ring, a so-called Einstein Ring. Here are a few examples of Einstein rings, images (in visible light) taken by Hubble. Some are only partial because of misalignment.

Wouldn’t it be great to find out if the image of SPD.81 is also an Einstein ring? Then we need a much higher resolution then the (already large) 3.5 meter mirror of Herschel could give us.

Alma can help us! ALMA stands for Atacama Large Millimeter/submillimeter Array. It is a collection of 66 radio telescopes (with 12 and 7 meter antennas), located at 5000 meter altitude in Chili. Here is ALMA

Technically it is called an (astronomical) interferometer. To keep it simple: the radio telescopes work together in such a way that they effectively combine to a huge mirror of many hundreds meters or even kilometers diameter. The telescopes can be moved around. The high altitude has been chosen because the climate in the Atacama desert is extremely dry, crucial for observations in the millimeter/submillimeter range. The maximum resolution has been described by the Alma astronomers as being “about the same as seeing the rim of a basketball hoop atop the Eiffel Tower from the observing deck of the Empire State Building“.

Here is Alma’s result for SDP.81, published a few weeks ago. An almost perfect Einstein ring! Keep in mind that this radiation is invisible, the red color has been added for the dramatic effect. And the visible light of the lensing galaxy is not recorded by ALMA.

And here is a combination of three images. The left image is taken by the Hubble space telescope. The lensing galaxy is visible. The middle picture shows the Alma result, in more subdued colours. And the third picture?

The Einstein ring in the middle picture is a “distorted” image of SDP.81. But, assuming a (simple) model for the gravitational lens in between, you could try to reconstruct the “real” image. And that’s what has been done with the third image as result.

An (approximate) image of the SDP.81 galaxy how it was, almost 12 billion year ago, when the Universe was still young. Some structure is visible, the bright parts are regions of dramatic star formation.

Amazing!

Close Encounters

Posted on February 28, 2015 by janstu

The Close Encounter concept has been introduced by ufologists, people who believe in ufo’s and aliens. You will not be surprised that I don’t, although, to be honest, the Spielberg movies E.T. and Close Encounters of the Third Kind, belong to my absolute favourites….:-)

The close encounters in this blog post are different and more prosaic . Not between humans and aliens, but between spacecraft and “celestial bodies”. In the past fifty years hundreds of close encounters have taken place, with spacecraft flying by, orbiting or even landing on planets, moons, comets and asteroids in in our solar system. If you are interested in the whole list (314! and counting), surf to NASA’s National Space Science Data Center and select “Planetary Science”.

In this year there will be two memorable and exciting close encounters.

DAWN

Next week ( 6 March), the Dawn spacecraft will enter orbit around the asteroid Ceres. Here is an artist impression of Dawn and its travel to Ceres, starting already in 2007

The asteroid belt is located between the orbits of Mars and Jupiter. Ceres is, with its diameter of 950 km, the largest of the asteroids. When it was discovered in 1801, it was considered a planet for some time. As you see, on its way to Ceres, Dawn has first explored Vesta, the second-largest asteroid (diameter 525 km). Here is a composite image of Vesta taken by Dawn. Note the three craters, nicknamed the “snowman” and the “bump” at the south pole, a mountain twice as high as Mount Everest…:-)

Dawn left Vesta in September 2012 and is now closing in on Ceres. Here is a picture taken by Dawn ten days ago, on 19 February. Note the two bright spots. The scientists have no clear idea yet what they are, and of course they are getting excited…:-)

Ceres is the final destination of Dawn. The coming months it will explore the surface of Ceres from various distances and finally settle down in a stable orbit (July 2015). You can follow Dawn on the Dawn Blog

NEW HORIZONS

On 19 January 2006 the New Horizons spacecraft was launched from Cape Canaveral. Destination: Pluto, at that time still the ninth planet of our solar system. But not for long, because later that year Pluto was degraded to the status of dwarf planet, together with Ceres. The left picture shows the trajectory of New Horizons, with its actual position on 28 February, the right picture gives an artist impression of the spacecraft closing in on Pluto and its moon Charon.

After passing Jupiter in 2007, the spacecraft has gone into hibernation for considerable times, to save energy. Every now and then waking up to let Earth know that it was still alive…:-). Last year in December, it became fully awake again.

As you see, Pluto is an outsider, with its very elliptical orbit. We know consider it a member of the Kuiper Belt. The spacecraft will fly by on 14 July this year and come as close as ~ 10.000 km! How will Pluto look like? Here is an artist impression of Pluto’s surface, its moon Charon and the Sun. Yes, that is our Sun, not much more than a bright star. Communication with New Horizons takes more than 4 hours, one way.

If the spacecraft keeps functioning, we will know a lot more about Pluto after the fly by. Exciting!

New Horizons will not go into orbit, just fly by. With the little fuel left, it will try to visit a few more members of the Kuiper Belt, and then leave our solar system, like the two Voyagers before. But that is a topic for another post.

ROSETTA

One more memorable event in 2015. I have reported a few times already about Rosetta, now in orbit around the comet 67P. This comet will reach its perihelion (closest to the Sun) in August this year. Already part of the comet is evaporating (forming the famous “comet tail”). Rosetta is still exploring the comet from various distances. The left picture, taken from far, shows the evaporation. The right picture is a close-up from the surface, taken from a distance of 8.9 km only!

The location of the Philae lander is still not accurately known. The scientists are hoping that soon this lander will get enough sunlight (it is probably in the shade of a rock wall) and will wake up again. Let’s keep our fingers crossed..:-)

Meet your great-(~10 million times)-grandmother

Posted on January 20, 2015 by janstu

In my blog The Tree of Life, published a few months ago, I wrote about the Last Common Ancestor (LCA) of all placental mammals, that it was a shrew-like animal, living about 65 million year ago. Terrestrial, with insects and fruits as food.

Yesterday Yale University has published an interesting update. Our ancestor most probably was not terrestrial, but lived in trees. More a squirrel than a shrew. This conclusion was drawn, based on a study of fossil ankle bones of Purgatorius as our LCA was named.

Of Bacteria and Men

Posted on December 23, 2014 by janstu

My recent Tree of Life post described how all living creatures share a common ancestor. Both Homo Sapiens and the E. Coli bacterium in his bowels belong to the same “extended” family!

In that post I promised to write another blog about bacteria and the human body. Here it is..:-)

We humans are multi-cellular organisms consisting of roughly 10 trillion cells. For those not familiar with the naming of big numbers, one trillion = 1000 billion = 1000000 million. And for comparison, the global human population is at the moment ~ 7.3 billion, so there are ~ 1500 times more cells in your body than there are people living on our planet.

Bacteria are single-cell organisms. How many bacteria do we have in and on our body? A staggering 100 trillion, 10 times as many as we have body cells! They can be found on our skin, on our teeth, basically everywhere, but most of them live in our bowels, the so-called gut flora . The size of these bacteria is roughly 10 times smaller than an average human body cell, their total mass is estimated to be 1-2 % of our body mass. Mind you, that is still a lot, about 1 kg of your body mass is bacterial!.

Probably you will have been taught that bacteria are bad and dangerous. Wash your hands, keep everything clean, etc. And of course there are bacteria that can harm you, even kill you. But most of the bacteria in/on your body are harmless and many are even needed for your survival. You would die without your gut flora!

Here are a few things your gut flora will do for you:

The bacteria will do part of the digestion and help forming your stool
They are important to build your immune system and keep it in good order
They will fight harmful (pathogen) bacteria
They are needed for the production of Vitamin-K
Etc, etc

Together, all of the bacteria in the body would be the size of a large liver, and in many ways, scientists say, this microbiome (as the whole community of microorganisms in our body is often called) behaves as another organ in the human body: the Forgotten Organ…:-)

As the importance of our microbiome has been recognised more and more in the last decades, some scientists nowadays consider us as superorganisms or see us as an ecosystem!

Or, as a microbiologist recently formulated it, in a rather extreme way: “we would do well to begin regarding the human body as “an elaborate vessel optimized for the growth and spread of our microbial inhabitants.”

A project of the US National Institute of Health, the Human Microbiome Project has been researching the human microbiome. Here is a survey of what they found (click on the picture to see details).The various parts of our body have different bacterial communities.

What about a baby, is it born with a gut flora? No, the womb is sterile (although maybe not 100%). But as soon as the baby has left the mother, the bacterial invasion begins and within days the gut flora is there. Essential to build the immune system of the baby!

Interesting detail: the composition of the gut flora is different for Vaginal delivery and Caesarean section delivery. Now it is well known that babies delivered by Caearean section run a higher risk of asthma, allergies and several other health risks, because of the different gut flora. Here is an interesting solution

Can you believe it…:-)? It is true.

What about this. The Clostridium difficile bacteria is a common bacteria in soil, but can also live in your bowels. Pathogenic strains of this bacteria can cause diarrhea and inflammation of the colon, especially when the normal gut flora has been damaged by antibiotic treatment. The bacteria itself is resistant against most antibiotics, so it takes over the gut flora. Here is a picture of the bacteria.

Infection with C. Difficile can be life-threatening, it kills approximately 14000 people yearly in the USA.

A promising solution? Fecal transplantation therapy. Or, in common English: Stool transplant! Take some of the feces of a healthy donor and put it in the colon of the patient. It often works!!

The bacteria in the stool are able to restore the balance in the compromised gut flora of the patient.

Can you believe it…:-)? It is true. Here are some success stories: The Power of Poop

Here is Rosetta again! (updated)

Posted on November 10, 2014 by janstu

In two earlier posts I have reported about the exciting space adventure of Rosetta, a spacecraft launched in 2004 with as destination a comet, the 67P/Tsjoerjoemov-Gerasimenko. The first post, Wake up, Rosetta!, described how, after a hibernation of more than two and a half years, Rosetta woke up in January 2014, according to plan.

The second post, Rosetta meets 67P, published last August, reports how Rosetta successfully goes into orbit round the comet. It turns out that the comet has a strange shape, like a rubber bathtub duck. Here is a picture, taken on 19 September at 28.6 km from the center of the comet. The head points to the right. If you look carefully you will see a kind of smoke coming from the “neck” of the comet. That is the coma, part of the comet material is evaporating because it is approaching the sun. Later, closer to the sun, 67P will develop the characteristic comet “tail”. The comet is rotating with a period of 12 hours and 36 minutes.

The last few months the scientific instruments on board Rosetta have already been busy. For example analysing the composition of the “coma” smoke. With interesting results, finding not only water and carbon dioxide, but also methanol, ammonia and hydrogen sulphide. Here is an interesting blog about The “perfume” of 67P. Quote: If you could smell the comet, you would probably wish that you hadn’t

But the ultimate goal of the expedition is to land a module on the comet itself! This module has been called Philae and you can see it here still attached to Rosetta.

The last few months, the scientists have been working hard to find a suitable landing site for Philae. That has not been a simple job, because of the complicated structure of the comet. The landing site should be relatively flat and smooth. Several options have been studied, finally the decision was made to choose location J, on the head of the duck in the picture below.

The landing site has now been renamed Agilkia. Why? Google and find out yourself 🙂 Hint: there is a relation with Rosetta and Philae.

The critical landing operation will take place on Wednesday November 12. At 8:35 GMT Philae will be deployed from Rosetta and start its slow fall to the comet. It has no thrusters that can change its course, so ultimate precision is required in the timing of the separation. Keep also in mind that the distance between earth and the comet is at the moment about 500 million km, so signals take time to reach Rosetta. To be exact: 28 minutes and 20 seconds one way! So it will be 9:03 GMT before we know if the separation has been successful.

Falling to the comet? Yes, because the gravitational attraction of the comet is very small, but it exists. The falling proces willl take about 7 hours! And the speed at landing will be “only” ~ 1m/s. For comparison, that is the speed an object would get here on earth, when it falls 5 cm!

As soon as Philae touches the surface of the comet, two harpoons will be fired down to anchor the module. Otherwise it might bounce back into space! Here is an artist impression of a successful landing.

The two red lines under Philae are the harpoons. The construction of the three supporting “legs” allows landing on moderate slopes. If the slope is steeper than 30 degrees, the Philae might topple over, resulting in failure. The whole procedure is considered a risky one, success estimates of 75% “only” have been mentioned..

So let us keep our fingers crossed Wednesday! Malaysian time is GMT + 8 hrs, Dutch time is GMT + 1 hr. Here is the ESA control room. How many nails will be bitten on that day, waiting seven hours, while you can do nothing…:-)?

On Wednesday there will be a live broadcast of the landing procedure

UPDATE 12 NOVEMBER

5am GMT

The Live broadcast has started already. It is still early in Darmstadt, people are arriving in the ESOC control room, where it is obviously quite cold…:-) Many sniffy people.

Here is a diagram of what will happen today. As I explained in my post, after separation Philae will “fall” to the comet. No course correction possible after separation, so utmost precision is needed

The last few days pictures have been taken by Rosetta with amazing details. Click here for a collection. Here is a spectacular one.

7:30 GMT

Just watched an interview with Gerhard Schwehm, mission manager of the Rosetta project. Now retired. I did not realise that the project started in 1985, almost 30(!) years ago. Less than one hour now until separation.

8:05 GMT

I have been naive..:-) Thinking that at this moment the command should be sent to Rosetta to deploy Philae (because it takes 28 minutes for the signal to reach Rosetta). But of course they will not do it that way..:-) Rosetta has been programmed to deploy Philae at 8:35am ! Around 9am GMT the ESOC will know if that separation has been successful.

8:35am GMT

At this moment, 511 million km away, the Philae is starting its fall to the comet 67P. In spite of a problem that has been found in the lander. As explained in my post, the Philae could bounce back after touching the surface of the comet. Therefore two harpoons are fired at touchdown to anchor it. Also, on top of the Philae, an amount of gas should be released, giving the Philae an extra push to the surface. It seems that this “thruster” doesn’t work properly.So everything will now depend on the harpoons.

9:05am GMT

Separation is succesfull!!

Waiting. Tense

Relief. Hugging

From now on, the Philae is on its own. In two hours time hopefully contact will be reestablished between Rosetta and Philae

11:10am GMT

Contact established between Philae and Rosetta! Great! This is a bigger step than the deployment. Philae is too weak to communicate directly with Earth, it has to do that via Rosetta. And it did! So now we can follow its descent to the comet, and it may even be able to send pictures.

Tension and relief again..:-)

2:20pm GMT

The first image taken by Philae of Rosetta, just a short time after deployment. Unprocessed, so not high quality, but convincing proof that Philae is on its way to 67P

2:40pm GMT

Telemetry data from Philae show that it is following the calculated trajectory accurately. The landing will be the most critical part. Everybody at Esoc keeps his/her fingers crossed.

Here is an image taken by Rosetta’s Osiris camera of the descending Philae lander. Amazing. The landing arms are out.

3:30pm GMT

Waiting now for news about the landing. Personally I do no like the optimistic way of talking about success. There is a reasonable chance of failure, and then the disappointment will be huge.

4:05pm GMT

Success? Or not? It seems Philae has landed. Congratulations

And within minutes the news is spreading all over the world…:-)

UPDATE 14 NOVEMBER

We know now that the Philae has really landed, but not without difficulty! The harpoons meant to anchor the lander, did not fire, so the lander bounced back after touchdown. Because of the low gravity of the comet, it took almost 2 hours before the second touchdown! Then, a few minutes later, the third and final touchdown. The first bounce took the lander up, about 1 km vertically, but also possibly the same distance horizontally. So at the moment the scientists are not sure where actually the Philae landed! During a live broadcast, 13-11, one of the lead scientists explained that the intended landing location was the red square (see below). But after the two bounces, the probable location is now within the blue “lozenge”

Because the Philae is not anchored, some of the planned experiments (like drilling to obtain and analyse some comet material) will be risky, as the lander might loose its balance and topple over.

It seems that the Philae has landed in a location that is more rocky than intended, maybe even beside a cliff. Those rocks may obstruct sunlight from reaching the solar panels of Philae. At the moment Philae is using the energy of its batteries, but soon it will depend on solar energy.

So there are minor(?) problems, which can hopefully be solved. Still the landing is an awesome achievement and at the moment the lander is already collecting scientific data and sending them to Rosetta. Also pictures of the surroundings have been taken. Here are first results, not yet fully processed. To the left a series of six “panoramic” pictures. On some of them a foot of the Philae can be seen. The collage to the right shows the same pictures, but with Philae superimposed.

The Tree of Life

Posted on November 6, 2014 by janstu

The Evolution Theory of Darwin is now generally accepted, although an astonishing 42% of the American population still thinks that the Christian God created humans more or less in their present form, about 10.000 year ago, according to a Gallup poll, held in May this year!

In 1860, after Darwin had published his book “On the Origin of Species, a debate was organised in Oxford between proponents and opponents of this new theory. Supposedly in this debate Bishop Wilberforce asked proponent Huxley whether it was through his grandfather or his grandmother that he claimed his descent from a monkey

Huxley is said to have replied that he would not be ashamed to have a monkey for his ancestor, but he would be ashamed to be connected with a man who used his great gifts to obscure the truth.

Actually both were wrong in assuming that humans descend from monkeys. Humans and monkeys have a common ancestor which may have resembled neither a human nor a monkey. Our closest relatives are the chimpanzees and the bonobos and our Last Common Ancestor (LCA) is estimated to have lived about 6 million years ago. For the LCA with the gorilla we have to go back ~ 7 million year, for the orang utan ~ 14 million year and for the gibbon ~ 18 million year.

Here is our extended family, in a diagram and as a collection of (baby) photos.

Homo: Humans Pan: Chimpanzees & Bonobos Gorilla: Gorillas Pongo : Orang Utan Hylobates: Gibbons

Of course the story does not end here. Our extended family belongs to the class of the “placental” mammals, together with mice, elephants, whales and bats and more than 5000 other species. The LCA of this (sub)class has lived around the time that an asteroid impact in Mexico may have caused the extinction of the dinosaurs, about 65 million year ago.

Last year an interesting article was published in Livescience: Meet Your Mama: First Ancestor of All Placental Mammals Revealed . It is an attempt, using advanced techniques, to determine the age of our Last Common Ancestor. In this article even an artist expression is given of our LCA (by palaeoartist Carl Buell )

Now, look at this picture carefully. This could be the (maternal) ~ 10 million-greats-grandmother of every living mammal, including you and me! Think about that for a while. You came from the womb of your mother, as she did from the womb of your grandmother. Repeat that ~ 10 million times and you end op with this shrew-like critter.

The Mammals are a class in the (sub)phylum of the Vertebrata, which contains six more classes (birds, reptiles, amphibians and three classes of fishes). Also here there has been a Last Common Ancestor, living somewhere around 500 million year ago. May have looked like a kind of segmented worm, with a gut, a mouth and an anus…:-)

Look at this interesting way to show the development of the seven vertebrate classes. To the left you see the geological eras Cambrium, Perm, Trias etc. The thickness of the various classes indicates the number of families in the class.

Notice the sudden change in thickness at certain times. They mark mass extinctions.. During the Perm-Trias extinction ( ~ 250 million year ago) numerous families and species became extinct. The other extinction shown is the one caused by the asteroid impact, 65 million year ago. Note the reduction of the reptile class (dinosaurs!)

The Vertebrata phylum belongs to the kingdom of the Animalia, together with eight other phyla. The most important of them are the Arthropods (insects, spiders, lobsters, centipedes) Sponges, sea urchins, jellyfish, earthworms are all animals and have their own phylum.

Confused by all these concepts like family, class, phylum, kingdom? This part of biology is called taxonomy Here is a diagram of our human lineage.

To keep it simple, I have skipped the category Order (we are Primates), taken the sub-class Placental Mammals and the sub-phylum Vertebrata, because the term is more familiar than Chordates.

So we humans are a member of the kingdom Animalia. Together with how many other species? Present count is ~1.5 million (mostly insects…haha) Estimated total animal species count between 2 and 20 million…

The kingdom of animals. Are there more kingdoms? Yes, there is also the kingdom of plants and the kingdom of fungi. All three contain multi-cellular organisms. And there are other kingdoms of unicellular organisms, like the paramecium, almost always present in stagnant water, and visible under the microscope

Keep in mind that there has been a Last Common Ancestor of you and this amoeba-like critter!

Why are these kingdomscombined together? Because they share a very important property: their DNA is contained in a separate part of the cell, the nucleus. These kingdoms form the domain of the Eukaryota Here is a visual representation of the kingdoms in this domain.

Again, keep in mind that there has been a LCA of all the organisms in this picture Although we have to go back far in time…:-) About 2 billion years, there is still a lot of discussion going on about the timing. But it is clear that developing a nucleus containing the DNA and organising the various functions of the cell was a major breakthrough in the evolution of life.

Do cells exist nowadays that do not have a nucleus? Sure! There are two more domains where the cells have no nucleus. One of them will be familiar to everyone, the domain of the Bacteria. The other one is the domain of the Archaea, also a kind of bacteria and only recognised as a separate domain during the last decade. Click here if you want to know more about the differences between the two (warning, very technical).

Bacteria are small organisms but there are many of them. The number of different species is unknown, estimates vary between 10 million and 1 billion…! They are everywhere! There are typically 40 million bacteria in a gram of soil and a million bacteria in a millilitre of fresh water. And don’t forget the bacteria in our own body. There are about ten times more bacteria in our body than there are body cells! On average about 2 kg in an adult human body, mainly in your gut. And important for your digestion, you would die without them.

Here is a picture of the most common bacteria in your gut, the E. Coli bacteria. I will write a separate post later about bacteria and the human body.

So, finally we have arrived at the beginning of life. About 3.5-3.8 billion years ago there lived the Last Universal Common Ancestor (LUCA) of every organism living now. We do not know much about it. It may have lived in the deep sea, near to a volcanic vent. Read Four Billion Year-Old Mystery of Last Universal Common Ancestor Solved for more information. Here is a diagram from this site, showing the first major evolutionary split, in Bacteria and Archaea .

And here is the tree of life, showing the split in the three domains. First the split in Bacteria and Archaea, with the Eukaryota branching off from the Archaea. Note that the Kingdoms of Eukaryota in the graph below have often different names from the names in the visual representation above. A clear sign how this field of evolutionary biology is still in development.

A much more detailed tree of life, although looking less like a tree, you can see below. Click here for a larger version. In blue the domain of bacteria, in green the Archaea and in red the Eukaryota. Each domain showing some of its kingdoms in different shades. Try to find homo sapiens..:-) And notice how huge and complicated the domain of the Bacteria is.

The names in the outer circle of this diagram are representative species in their kingdom. You can spend hours checking details in Wikipedia…:-) For example Anopheles Gambiae : Mosquito, Oryza Sativa: Rice, Takifugu rubripes : Pufferfish, etc.

That a single tree of life can be constructed for all the living organisms, suggests that life has only started once on earth. If life arose repeatedly then all of the separate origins must have disappeared without trace.

All living organisms belong to one big family with a common past of ~3.5 billion years. Isn’t that a nice conclusion for this post…:-)?

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Much of the information in this post comes from the monumental book The Ancestor’s Tale, written in 2004 by Richard Dawkins

The Ig Nobel Prizes

Posted on September 22, 2014 by janstu

Last week for the 24th time the yearly Ig Nobel prizes have been awarded. The ceremony took place at the prestigious Harvard University in Cambridge, Massachusetts , USA

The Ig Nobel prizes?

Here is what the supporting foundation for Improbable Research says about it:

IG Nobel prizes are awarded for research that makes people LAUGH and then THINK

This year the Ig Noble prize for physics has been given to the Japanese scientist Kiyoshi Mabuchi of Kitasato University for studying the hazards of stepping on a banana peel! Here he is, during the official ceremony

Don’t underestimate his research! Here is the official paper: Frictional Coefficient under Banana Skin.

A few more examples of Ig Nobel prizes.

2014 Neuroscience: to Jiangang Liu, Jun Li, Lu Feng, Ling Li, Jie Tian, and Kang Lee, for trying to understand what happens in the brains of people who see the face of Jesus in a piece of toast.

2013 Biology/Astronomy: Marie Dacke, Emily Baird, Marcus Byrne, Clarke Scholtz, and Eric Warrant, for discovering that when dung beetles get lost, they can navigate their way home by looking at the Milky Way.

2012 Medicine: Emmanuel Ben-Soussan and Michel Antonietti, for advising doctors who perform colonoscopy how to minimize the chance that their patients will explode

Click here for the complete list. In the beginning the prizes sometimes had a sarcastic undertone, like for example

1998 Physics: Deepak Chopra of the Chopra Center for Well Being, La Jolla, California, for his unique interpretation of quantum physics as it applies to life, liberty, and the pursuit of economic happiness

But now it has become more serious, the prize winners eagerly travel (at their own expenses) to Harvard to attend the ceremony and the prizes are given by “real” Nobel Prize winners.

There is even one scientist who has won BOTH the Ig Nobel prize AND the Nobel prize! Andre Geim, a Soviet-born Dutch-British (!) physicist, won the Ig Nobel prize for physics in 2000 experimenting with magnets to levitate a frog. Here is a picture of the poor critter. If you are wondering how this is possible, it is because of diamagnetism

Ten years later, in 2010, Geim received the Physics Nobel prize for his research about the new wonder material of graphene, a two-dimensional layer of carbon atoms.

The way he and his collaborator Novoselov managed to make a single layer of carbon atoms? They used Scotch tape!

Ok, here is one more Ig Nobel prize…:-)

2009 Public Health: Elena N. Bodnar, Raphael C. Lee, and Sandra Marijan of Chicago, US, for inventing a bra that can be quickly converted into a pair of gas masks—one for the wearer and one to be given to a needy bystander

By the way, ever heard about the Darwin Awards? Maybe a suitable topic for another post…:-)

Where does the Moon come from?

Posted on August 13, 2014 by janstu

Last week it was full moon, and not just an ordinary one, but a perigee full moon, often popularly called a “Super Moon”. The orbit of the moon around the earth is elliptical, so the distance between moon and earth varies between 363.104 km (perigee) and 406.696 km (apogee). When a full moon occurs at perigee, the moon looks larger and brighter. It’s not a rare phenomenon, 9 September this year will be the next perigee full moon, and June 2013 there was another one. It’s a bit of a media hype.

My friend Chuan took a beautiful picture of this perigee full moon, in the middle of the night, with his point and shoot camera(!), handheld, 24x zoom.

The dark regions are called Mare (Sea) because in the past people believed that there was water on the moon. Actually they are basaltic plains, formed by ancient volcanic eruptions. Huge craters mark the places where meteorites have hit the moon. Here is a map of the moon with the names of craters and seas.

We can see only one side of the moon because the moon is “tidally locked” to the earth, always showing the same face to us. This interesting phenomenon deserves a separate post..:-) So how does the other (“dark”) side of the moon look like? It’s only after the start of the space age that we were able to explore. With a surprising result. Here is the other side of the moon

A lot of craters, but no “seas”. Why so different? Which leads to another, more basic question, where does the moon come from? Was it “born” at the same time as the sun and the other planets, ~4.5 billion years ago? Many hypotheses have been formulated, here is the theory that is generally accepted at the moment. It is called the Giant Impact Hypothesis

Not long after the formation of the solar system, there was another planet, about the size of Mars, which collided with the (young) Earth. Here is an artist impression of this collision.

This hypothetical planet has been named Theia, after a Greek goddess, the mother of Selene, the goddess of the moon. The effect of this dramatic collision was that a large part of Theia and Gaia, as the young Earth is sometimes called, melted together, forming the present Earth, but another part of Gaia and Theia was thrown out during the collision and coalesced into the Moon.

So powerful was this collision that the new Moon and probably also part of the Earth consisted of molten magma. The Moon, being smaller, cooled faster, and because of the heat of Earth and the tidal locking, the near side of the moon got a thinner crust than the far side! According to this theory that might be the reason that the near side has had more volcanic activity than the far side. There are many more arguments in favour of this giant impact hypothesis.

Of course the next question is then, where did Theia herself come from? A very promising idea is that this planet might have been formed in about the same orbit as Gaia. In 1772(!) the French mathematician Lagrange studied the properties of rotating systems, like the earth orbiting the sun. He discovered that there exist points in such a system, where other objects can exist in a stable way. There are five such points, nowadays called Lagrange points

In the Lagrange points L4 and L5 the gravitational force of Sun and Earth balance in such a way, that objects will corotate with Earth around the Sun. During the formation of the solar system, mass could have accumulated in for example L5 and formed Theia. Through the disturbance by other planets (Venus for example), this planet could, after millions of years, leave L5 and collide with Earth.

Just skip this last part if you find it too complicated…:-)

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